Hippocampus and jejunum biochemical parameters related to physiological ageing of neurons in rats fed diets with copper nanoparticles and different fiber types

One of the more important factors responsible for synaptic dysfunction of neurons is a neurological ageing. It is a natural consequence of occurrence of biochemical pathways in cells, promoting oxidation processes, an increase in the amount of free oxygen radicals that damage DNA, disorders in calcium ion homeostasis, interactions between lipids of cell membranes, formation of neurofibrillary tangles and deposition of toxic protein deposits. Diet modifications can delay neurometabolism disorders that occur as a result of aging, as well as limit the development of neurodegenerative diseases. The aim of this study on rats was to verify the hypothesis regarding the effect of dietary addition of copper nanoparticles (CuNPs; instead of standard CuCO₃) in combination with various dietary fibers on changes in hippocampus and jejunum biochemical parameters related to metabolic disorders appearing with neurological ageing in rats. Male rats were fed a control diet with containing fiber α-cellulose and a standard or enhanced content of Cu provided as CuCO₃ (6.5 or 13 mg/kg diet). The diets of other groups were deprived of CuCO₃ and the animals were fed diets supplemented with two CuNPs aforementioned doses, and additionally combined with four different types of dietary fiber: α-cellulose (control fiber), pectin, inulin or psyllium (Plantago psyllium). The addition of dietary CuNPs increased the level of acetylcholinesterase (AChE) and decreased the levels of Tau protein, glycosylated AChE (GAChE) and Ca/calmodulin dependent protein kinase II alpha (CAMK2α) in the examined organs. To sum up, both applied doses of CuNPs, 6.5 mg and 13 mg per kg of a diet, can beneficially modulate some important parameters describing metabolic and neurodevelopmental status in the hippocampal and small intestinal tissue of rats. With regard to the fiber type added to rats’ diet, the Plantago psyllium fiber strengthened the mentioned effects of copper nanoparticles. The observed effects should be confirmed in a model study of neurodegeneration.